Enabling Fanuc 3D Interference Check: Parameters and Setup

Introduction to 3D Interference Check

A catastrophic hard collision of a high-speed spindle or tool holder into a spinning chuck or a rigid jig is a devastating shop floor failure that instantly shears cutting tools, damages spindle bearings, and creates an immediate scrap part. When operators run custom setups on multi-axis CNC machines, coordinate boundaries like traditional stored stroke limits are often insufficient to prevent collisions because they only check simple coordinate envelopes rather than dynamic, complex solid volumes. During rapid movements, a physically large but digitally invisible tool can easily plunge directly into a work-holding fixture. Implementing real-time, three-dimensional solid model simulation processed natively inside the CNC is the only way to safeguard the machine and ensure continuous operation. Fanuc addresses this production risk by integrating a built-in 3D interference check function that continuously calculates the spatial proximity between dynamic models and static environmental objects before a physical collision can manifest. Unlike traditional stored stroke limits configured via the g22-g23-stored-stroke-limit commands that only create invisible cubical boundaries, this safety system monitors actual geometry. To enable and configure these settings, technicians must understand how to access and modify the system registers, similar to the process described in the fanuc-parameters-and-pwe guide.

Technical Summary

Aspect	Details
Command Code	N/A (Continuous parameter-based; updates via M06 / T_ and G10 L75 / L76)
Modal Group / Modality	Background safety check / Non-modal data registration
Brands	Fanuc
Critical Parameters	Parameter 10930#0 (ICE), Parameter 10930#5 (IIA)
Main Constraint	Target figure data must be valid, and the total number of shapes in all targets (excluding the tool) cannot exceed 23, or Alarm PS0495 triggers. Setting 10930#5 (IIA) to 1 disables alarms for invalid figures, rendering tools invisible and risking collisions. Changes require power-cycling or toggling PMC signal TDICHG.

Quick Read: Key Operational Rules

• Continuous Background Monitoring: The built-in 3D interference check runs continuously in the background on Fanuc CNCs rather than relying on a specific activation G-code.
• Enable Feature: To activate the system, set Parameter 10930#0 (ICE) to 0, which enables the built-in 3D interference check function.
• Prevent Invisible Tools: Always keep Parameter 10930#5 (IIA) set to 0. If set to 1, the system will quietly ignore invalid tool figures, making physical tools invisible to the safety matrix and risking a collision.
• Commit Changes: After modifying any 3D figures or parameters, you must power-cycle the CNC controller or toggle the PMC signal TDICHG <G0519.4> to 1, or changes will not take effect.
• Shape Limits: Limit the total number of shape components across all check targets (excluding the active tool) to 23 or fewer to prevent Alarm PS0495.
• Avoid Active Registration Alarms: Do not stream tool registrations via G10 L75 or G10 L76 from a PMC window or FOCAS2 while a part program is running, as this triggers Alarm 0374.

Basic Concepts of 3D Interference Check

The practical programming effect of Fanuc’s Built-in 3D Interference Check is the total prevention of mechanical crashes through real-time, three-dimensional solid model simulation processed natively inside the CNC. Unlike traditional stored stroke limits that only create invisible cubical boundaries based on coordinates, this function actively monitors the complex polygonal geometry of the spindle, the cutting tool, the tool holder, and moving machine elements like the turret, table, and tailstock. As the machine executes the G-code, the CNC continuously calculates the spatial proximity between these dynamic models and static environmental objects such as a spinning chuck, a rigid jig, or the workpiece. Safe use requires programmers to meticulously manage the tool geometry size data and the 3D model assignments within the iHMI interface. A severe common failure cause occurs if a programmer inputs an invalid tool model or an improper offset into the tool management system without appropriate safety parameters enabled.

If parameter 10930#5 (IIA) is configured to quietly ignore invalid figures rather than raising an alarm, the CNC will blindly exclude that specific cutter from the interference matrix. Moving a physically large but digitally "invisible" tool towards the workpiece will completely circumvent the safety logic, rapidly plunging the tool directly into the chuck or a solid jig. This guarantees a catastrophic hard collision and an immediate scrap part. If properly parameterized, detecting an impending collision halts the axes instantly and generates an alarm code (such as an OT alarm) before any physical damage can manifest. Programmers and operators must also watch for the TDISD disable signal; if a ladder logic sequence temporarily forces this signal active to allow a tight tool change, the 3D check is entirely suspended, leaving the machine vulnerable if uncommanded movement occurs.

Command Structure & Addressing

To interact with and update the active 3D geometries, Fanuc controls use standard tool change commands and programmable data input blocks. Rather than having a specific G-code that toggles the interference check on or off during machining, the system runs continuously in the background. It dynamically links the active solid model representation to the physical tool call. When a tool index is commanded, the CNC automatically retrieves the geometric envelope defined in the tool manager and swaps it into the active interference model matrix. To write parameter data safely, you can refer to the guidelines in fanuc-parameters-and-pwe to enable parameter writing safely.

Alongside automatic tool change updates, programmers can update tool figures programmatically using special data input modes. By executing programmable data registration blocks, the system updates the tool management data, which in turn alters the interference tool figures. This is particularly useful in automated production cells where tool configurations are dynamically updated via external measurement sensors or automated loader interfaces. To configure the core behaviors of this system, technicians must configure specific system parameters that control the execution, alarm responses, and object limits. Similar to updating values in fanuc-tool-life-management-parameters, setting the correct parameters ensures the machine executes the updates correctly.

Syntax & Addresses

To call a physical tool and update its corresponding 3D model, program:

T_ ; or M06 T_ ;

To register tool manager data and dynamically update the interference tool figures, program:

G10 L75 ; or G10 L76 ;

System Parameters

Parameter	Description	Value Range / Options
Parameter 10930#0 (ICE)	Determines if the built-in 3D interference check function is Enabled or Disabled.	0: Enabled 1: Disabled
Parameter 10930#2 (ICT)	Sets the method used to detect that a tool offset number has changed.	0: PMC window function code 431 1: Tool management function with PMC window code 329
Parameter 10930#5 (IIA)	Dictates safety behavior if a specified tool offset number is invalid.	0: Alarm PS0492 is issued 1: No alarm is issued, and the invalid tool figure is ignored
Parameter 10930#6 (ENO)	Determines the maximum number of trackable environmental objects when the number of controlled paths is 1.	0: Three objects 1: Six objects
Parameters 10931 to 10959	Matrix of bit parameters that individually enable/disable the interference check between specific geometric pairs.	0: Enabled 1: Disabled
Parameters 10966 to 10971	Dictates the alarm response when an interference occurs between specific pairs.	0: OT (Overtravel) alarm immediately occurs 1: OT alarm does not occur; notified by a PMC signal instead
Parameter 10975#0 (OBD)	Dictates whether all movements of the object are prohibited when an interference is detected.	0: Not Prohibited 1: Prohibited

Brand Applications

Fanuc

On Fanuc systems, physical safety is managed via bit-level parameters and real-time Diagnostic (DGN) registers. The controller continuously monitors the spatial orientation of both static environmental objects and moving components. The 3D interference check operates continuously, relying on Parameter 10930#0 to turn the feature on or off, while Parameter 10930#5 determines how the system reacts to invalid tool models.

To update the active interference model during operations, the programmer uses standard tool index codes like T0101 or M06 T01. Programmable data update is performed via G10 L75 or G10 L76 commands, which register tool manager geometries directly to the active safety matrix.

Category	Identifier	Technical Specification & Operational Behavior
System Parameter	Parameter 10930#6 (ENO)	Determines environmental object capacity: 0 limits it to three objects, while 1 expands it to six objects.
System Parameter	Parameters 10931 to 10959	Bit parameters enabling (0) or disabling (1) specific geometric interference check pairs.
System Alarm	Alarm PS0492	3DCHK FIG. ILLEGAL: Triggered when the 3D figure data of a specified target is invalid or missing, and Parameter 10930#5 is 0.
System Alarm	Alarm PS0493	3DCHK AXIS ILLEGAL: Triggered if the move axis data of a specified 3D target is invalid.
System Alarm	Alarm PS0494	3DCHK FUNCTION INVALID: Triggered at power-on if 3D check is disabled by Parameter 10930#0 (ICE) but configured for use.
System Alarm	Alarm PS0495	3DCHK TOO MANY FIGURE: Triggered if shapes in all check targets (excluding the tool) exceed 23.
System Alarm	Alarm 5360	TOOL INTERFERENCE CHECK ERROR: Triggered if an interference is caused by G10 data input or file input.
Version Difference	Multi-path configurations	Default object name uses Machining Center (M-type) name if all paths are M-type; Lathe (T-type) name overrides if any path is T-type.
Version Difference	Single-path configurations	Can expand environmental object capacity from 3 to 6 by setting Parameter 10930#6 (ENO) to 1.

Warning: Temporarily setting Parameter 10930#5 (IIA) to 1 will quietly ignore invalid geometries, making physical tools invisible to the check matrix. If an operator executes a machining cycle under this state, the physical cutter will crash into fixtures, destroying the workpiece and causing major mechanical damage.

Brand Comparison

Generation / Configuration	Default Object Naming Behavior	Environmental Object Capacity	Parameter / Override Condition
Multi-path (All M-type)	Uses Machining Center (M-type) name exclusively for default "OBJECT" name.	Determined by system configurations.	Controlled by path configurations.
Multi-path (Mixed or Single T-type)	Lathe (T-type) default "OBJECT" name overrides the system if even a single path is configured as T-type.	Determined by system configurations.	System-wide override behavior.
Single-path (Default vs. Expanded)	Default naming matches machining center configurations.	Default capacity is 3 environmental objects; setting Parameter 10930#6 to 1 expands capacity to 6 environmental objects.	Controlled by Parameter 10930#6 (ENO).

Technical Analysis of Fanuc Features

Fanuc profoundly distinguishes its 3D interference architecture through its highly granular check-matrix parameterization, its ability to decouple physical stopping from diagnostic alarms, and its native interface integration. First, instead of employing a global "on/off" collision envelope that wastes processing power, Fanuc utilizes a massive parameter array (10931 through 10959) that provides individual bit-level control over every possible intersection pair. A programmer can independently enable or disable mathematical checks between Tool Holder 1 and Object 2, or Tool 3 and Tool 4, ensuring the CNC processor only calculates intersections that are physically possible. Second, Fanuc allows for extreme flexibility during complex setups via parameters 10966 through 10971. Rather than forcing the machine into an absolute hard-stop alarm code when an interference is predicted, these parameters can be toggled to suppress the OT alarm and merely output a PMC notification signal (such as TDIHO1). This allows the machine builder to write custom ladder logic to gently pause the cycle or safely retract the axes autonomously, differentiating Fanuc's highly adaptive safety engine from strictly rigid collision-stop systems. Finally, Fanuc embeds the 3D modeling environment directly into its native iHMI and PANEL iH Pro interface; operators can map, visualize, and assign physical turret and jig graphics immediately at the CNC screen without requiring an external PC or simulation software to process the geometric data on the shop floor.

From a configuration perspective, multi-path setups handle default geometric naming depending on path types. If all paths are Machining Center (M-type), the system applies default M-type names. If any path is configured as a Lathe (T-type), the Lathe naming system overrides the entire control. For single-path machines, programmers can expand the tracked object capacity from the default three objects to six objects by toggling Parameter 10930#6 (ENO) to 1. This flexibility allows tailored setups for complex fixtures without incurring performance overhead.

Program Examples & Dry Run Verification

; Fanuc: Tool Update and Monitored Motion Sequence
T0101 ; Index tool 01 and offset 01
M06 ; Execute tool change and load 3D interference model
G00 X150.0 Z50.0 ; Rapid approach monitored by 3D check
G10 L75 ; Register tool manager data to update tool figures

Dry Run Execution & Verification

During a dry run, the operator activates the dry run switch and sets the feedrate override to a low value (e.g., 10%). The controller reads the T0101 and M06 commands to physically index the tool and update the active 3D interference check model. When the CNC processes the rapid traverse G00 X150.0 Z50.0, it continuously runs background collision algorithms. If any geometry overlap is predicted between the active tool holder, turret, chuck, or tailstock, the CNC halts motion instantly and raises an OT alarm before physical contact. The G10 L75 command updates the registered tool parameters in the database; because we are in dry run mode, the operator can verify that the updated figure is correctly processed on the iHMI screen before running an active program.

Error Analysis and Fault Codes

Brand	Alarm Code	Trigger Condition	Operator Symptom	Root Cause / Fix
Fanuc	PS0492	Triggered if the 3D figure data of a specified target is invalid or missing.	The machine halts and displays "PS0492 3DCHK FIG. ILLEGAL" on the screen.	Root Cause: Tool model files or fixture dimensions in the tool manager are corrupt or incomplete. Fix: Correct the figure data via the iHMI interface and ensure Parameter 10930#5 (IIA) is 0.
Fanuc	PS0494	Triggered at power-on if the built-in 3D interference check is disabled by Parameter 10930#0 (ICE) but the machine is configured to use it.	CNC fails to start or displays "PS0494 3DCHK FUNCTION INVALID" at power-up.	Root Cause: Parameter 10930#0 is set to 1 (Disabled) while other settings require active monitoring. Fix: Set Parameter 10930#0 to 0 (Enabled) and power-cycle the CNC.
Fanuc	PS0495	Triggered if the total number of shapes included in all check targets (excluding the tool) exceeds 23.	Axes are locked, and "PS0495 3DCHK TOO MANY FIGURE" is displayed.	Root Cause: The geometric model complexity or number of environmental objects exceeds processing limits. Fix: Simplify target models or disable unnecessary check targets.
Fanuc	Alarm 5360	Triggered if an interference is caused by G10 data input, file input, or changing figure data of a tool in the cartridge.	CNC interrupts cycle and displays "5360 TOOL INTERFERENCE CHECK ERROR".	Root Cause: A G10 block or file stream loaded a tool figure that intersects with another active model. Fix: Review G10 program inputs or manual data entry to correct coordinates.
Fanuc	Alarm 0374	Streaming G10 L75/L76 tool management registrations from PMC window or FOCAS2 simultaneously with an active program.	The CNC halts with "0374 ILLEGAL REGISTRATION OF TOOL MANAGER".	Root Cause: Concurrent tool management updates attempted during active program execution. Fix: Restrict G10 L75/L76 streaming to setup mode or when the part program is idle.

Application Note: Preventing Collision Hazards

A catastrophic hard collision and an immediate scrap part are the direct consequences of configuring parameter 10930#5 (IIA) to 1, which quietly ignores invalid tool figures instead of raising an alarm. In this bypass state, if a programmer inputs an invalid tool model or an improper offset into the tool management system, the CNC blindly excludes the cutter from the interference check matrix. The physical tool becomes digitally invisible, allowing the turret to plunge a large cutting tool directly into a spinning chuck or a rigid jig. To avoid mechanical damage, technicians must verify that parameter 10930#5 (IIA) remains at 0 so that invalid figures trigger Alarm PS0492. Operators must also monitor the state of PMC disable signal TDISD <G0518.3>; if a ladder logic sequence temporarily forces this signal active to allow a tight tool change, the 3D check is entirely suspended, leaving the machine vulnerable if uncommanded movement occurs.

Related Command Network

• M06 (Tool Change): This command initiates physical tool changes and automatically updates the active 3D solid model representation.
• G10 L75 (Tool Data Registration): This programmable data input registers tool manager data to dynamically update the active 3D interference figures.
• G10 L76 (Tool Figure Update): This data registration command updates physical tool geometries within the tool database.
• PMC Window Code 431 / Code 329: These codes check tool offset changes to ensure the 3D interference check utilizes the correct geometry.

Conclusion and Best Practices

Securing the machine environment against high-speed crashes requires strict management of 3D modeling parameters and a disciplined tool data update workflow. Operating with Parameter 10930#0 set to 0 and ensuring Parameter 10930#5 remains at 0 provides the necessary safety buffer. Technicians must enforce a mandatory power-cycle or toggle the PMC signal TDICHG <G0519.4> after any configuration changes to ensure the CNC actively processes the new geometries. By incorporating these safety practices, machine shops can eliminate collision risks, reduce downtime, and protect high-value CNC assets.

Frequently Asked Questions

How does Parameter 10930#5 (IIA) affect the safety of the 3D Interference Check?

Parameter 10930#5 determines whether the CNC raises a protective alarm when a tool has invalid or missing figure data. Set this parameter to 0 to ensure the machine triggers Alarm PS0492 and halts axes immediately, rather than ignoring the invalid data and running with a digitally invisible tool.

Why must the CNC be power-cycled or the PMC signal TDICHG toggled after updating 3D models?

Fanuc controllers load geometric models into active memory only during system initialization or when the PMC signal TDICHG is pulsed to 1. Program a PMC toggle script or perform a full power-cycle immediately after updating fixtures or tool graphics in the iHMI to guarantee the check matrix uses the updated models.

How can I resolve Alarm PS0495 (3DCHK TOO MANY FIGURE) on a single-path machine?

Alarm PS0495 occurs when the total number of shape components in your check targets (excluding the tool) exceeds 23. To resolve this, simplify the STL models of your fixtures or change Parameter 10930#6 (ENO) to 1 to expand the trackable environmental object capacity from three to six.